Dental plugger



(Ne Model.)

C. FOERSTER. DENTAL PLUGGER.

No. 352,456. Patented Nov. 9, 1886'.

w ai@ s fail W|TNESSESI "UNITED STATES r PATENT OFFICE.

CHARLES FOERSTER, OF PHILADELPHIA, PENNSYLVANIA.

DENTAL PLUGGER.

BPECIPICATON forming part of Letters Patent No. 352,456, dated November 9, 1886.

Application filed February 27, 1886. Serial No. 193,422. (No model.)

To all whom it may concern:

Be it known that I, CHARLES FoERsTER, a citizen of the United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented a new and useful Im-` adjusting the force of the blows, and certain other features are presented, as will be hereinafter fully set forth.

Referring tothe drawings, A represents the casing of a dental plugger; B, the iinger-piece; C, the tool or plugger, and D the tool-holder, the latter being retained in the piece B by means of a screw, E, which is passed through the piece, and a slot, F, in the holder, said slot being of much greater dimensions in the direction of the length of the instrument, that the holder has a greater play in the piece B, whereby when the tool is pressed against a tooth the upper or inner end of the holder projects beyond the inner end of the piece B, so as to receive the blows of the hammer of the instrument.

Within the casing A is a sliding cylinder, G, forming the holder of the hammer H, which is secured to said holder at the end adjacent to the inner end of the piece B, and carries a piece, J, of wood, lead, or other soft material, adapted to strike the tool-holder, the latter being of hard metal or material.-

Within the holder G is a rotary head, K, to which is secured a spindle, L, the upper or outer end of which is attached to the shaft M of a dental engine, whereby motion is communicated to said head K, the latter having a spiral flange, N, which bears against an inwardly-projecting iiange, P, of spiral form, secured to the end of the holder G opposite to the'hammer H, the spindle L passing freely through the center of said flange P. The

holderv G has a longitudinal groove or slot, a, in its side, into which projects a pin, b, on the inner face of the casing A, whereby rotation of said holder is prevented. The tool-holder D is forced outwardly by means of a spring, c, which bears against a shoulder on the inner face of the piece B and ashoulder on the toolholder.

Within the casing is a sleeve, Q, whose exterior is threaded, and through which freely passes the spindle L. On the sleeve is a crosshead, R, whose sides are formed with tongues d, which enter grooves e on the interior of the casing A, whereby rotation of the head is prevented. Encircling the sleeve between the head Rand iiange P is a spring, S, which bears against said head and iiange.

The portion T of the sleeve is unthreaded, and on the same is tted an eXteriorly-threaded nut, U, which rests against a shoulder, U', on the sleeve, and is screwed to the casing, preventing outward displacement of the sleeve. An interiorly-threaded nut, V, is screwed to the outer end of the sleeve Q, whereby the spiral flange N is held in contact with the spiral 4 flange P, said nut V tightening against the shoulder V on the' sleeve Q just outside of the nut U, for purposes to be hereinafter explained.

When the shaft M is operated, rotary motion is imparted to the head K. As the spiral iiange N of the said head rides on the flange P the latter is moved in the direction toward the cross-head R, the springs being compressed andthe hammer receding from the head of the tool-holder. As soon as the highest end of the spiral flange passes the termination of the flange P the latter is no longer controlled by the iiange N, and said flange P is thus tripped, whereby the hammer is forcibly impelled against the head of the tool-holder, and a blow imparted thereto and consequently to the tool. As the head K continues its rotation the hammer is again withdrawn from the head of the tool-holder, after which the flange is tripped, as before, and another blow imparted to the tool, these operations continuing as long as power is transmitted to the shaft M. As the nut V tightens against the shoulder V of the spindle, the nut U, which is located on the sleeve between the shoulder U and the nut V, is thus swiveled on the sleeve. vision the nut V and the sleeve may be rotated IOO- By this proas one by operation of the nut V, so that 'the crosshead R may be moved in either direction, whereby the tension of the spring S, and consequently the force of the blows of the hammer, may be adjusted.

The facing or filling J, of wood or soft material, on the hammer serves to reduce the noise of the blows on the tool-holder and deaden said blows, preventing harshness in the operation of the tool on the teeth.

Owing to the play of the tool-holder and the advance of the same beyond the inner end of the piece B, as seen by the dotted lines, Fig. 2,the blows of the hammer are exerted primarily and in the main on the tool-holder, instead of the finger-piece, avoiding battering of the latter. The flange P is not necessarily spiral; but the spiral form thereof is preserved, as it assists in guiding the holder G truein its advance motion.

Having thusdescribed my invention, what I claim as new, and desire to secure by Letters Patent, is Y 1. In a dental plugger, the hollow holder G, longitudinally movable in the casing A, and having the flange P, provided, with a spirallyinclined under face, secured to the upper part thereof, in combination with the rotary head K, secured `to the lower end of the spindle L,

and having the spiral flange N on its upper v face, the said spiral flanges P and N being in contact, the hammer H, secured to said holder G, and the spring S between the cross-head and upper portion of the holder, al1 substantially as described.

2. In a dental plugger, the casing A, in combination with the nut U', secured in the upper portion of said casing, the sleeve Q, swiveled in said nut, and having shoulders U and V and upper and lower threaded portions, the nut V, the cross-thread R, the rotary head K, having spindle L, passing through said sleeve Q, and holder G, all substantially as and for the purpose set forth.

3. In a dental plugger, the .casing A, with grooves e, in combination with the holder G, having hammer H and flange P, the swiveled screw-sleeve Q, with nut V, and carrying head R, having tonguesd, and spring S, interposed between said ange P and head R, substantially as andfor the purpose set forth.

CHAS. FOERSTER.

Witnesses:

J oHN A. WIEnERsHEIM, A. P. GRANT. 

